The family of a 21-year-old woman who died in an exceptionally busy A&E ward after taking diet pills are launching a legal challenge to overturn a coroner’s conclusion that she intended to kill herself.

Bethany Shipsey died at Worcestershire Royal hospital in February 2017 after swallowing tablets she had bought online from eastern Europe that contained the industrial substance DNP.

The senior coroner for Worcestershire, Geraint Williams, described the care Shipsey received as “significantly substandard” but found that she had intended to take her own life.

Shipsey’s parents, Doug and Carole, have instructed specialist lawyers to help them apply for a judicial review of the suicide conclusion.

Doug Shipsey, 52, said: “The inquest was difficult for us, listening to the failings in the care of our daughter being discussed while constantly thinking that she could have perhaps been saved.”

The family have suggested the overdose may have been a “cry for help”, pointing out that Bethany told her friends about her actions on Facebook.

Bethany, who had survived 14 previous overdoses, also posted that her “body can take it”, which her family argue suggests suicide was not her intention.

They say it is unclear how many pills Bethany took, and toxicology experts gave evidence that the level of DNP in her blood was low in comparison to other reported fatal overdoses.

Doug Shipsey said: “We just want to ensure that the law is applied correctly in our daughter’s case and that all the evidence is considered and reflected in the findings.”

Bethany had been diagnosed with borderline personality disorder, which her family say was a result of rape.

The family argue it was not proved beyond reasonable doubt – the standard needed for an inquest finding of suicide – that she meant to kill herself.

Oliver Carter, a specialist public lawyer at Irwin Mitchell, who is representing the family, said: “Doug and Carole have endured an incredibly difficult time which no parents should have to face. Ever since the inquest’s conclusion they have held concerns regarding the coroner’s ruling. While nothing will change what they have been through, they are determined to ensure this issue is properly considered and that the conclusion reflects the truth of what happened to Bethany.

“Inquest law is a hugely important area and the public need confidence that it is always applied correctly, particularly in the incredibly sensitive area of suicide.”